Loops In JAVA

Different loops in Java are:

1.While Loop
2.Do-While Loop
3.For Loop
4.For-each Loop

1.While Loop

   while loop for print numbers from 1 to 10:

        int a=1;                                //Initialization
        while(a<=10)                      //Conditional
        {
            System.out.println(a);
            a++;                                //incremental or decrement operator
        }

Disadvantage of while loop:it will generate infinite loop if you do not give incremental or decrement operator


2.Do-while Loop
       
        do while loop for print numbers from 1 to 10:
       
        int b=1;                                 //Initialization
        do {
            System.out.println(b);
            b++;                                //incremental or decrement operator
        }while(b<=10);                  //Conditional

3.For loop

        for loop for print numbers from 1 to 10:

        for(int i=1;i<=10;i++)       //Initialization,Conditional,incremental or decrement
        {
            System.out.println(i);
        }
      
4.For-each loop

        for each loop is used for Array,Arraylist,Hashmap..etc

        for each loop for print integer array:

        int array[]= {100,200,300,400,500};
        for(int i:array)
        {
            System.out.println(i);     //100,200,300,400,500
        }
      

        for each loop for print String array:

        String arrayString[]= {"test","test1","test2","test3"};
        for(String i:arrayString)
        {
            System.out.println(i);    //test,test1,test2,test3
        }

In Loop we can use two types of jumping statements

        1.Break
        2.Continue
       
        1.For loop for print numbers from 1 to 10 with break
       
        for(int i=1;i<=10;i++)       //Initialization,Conditional,incremental/decrement
        {
            if(i==5)
            {
                break;
            }
            System.out.println(i);          //1,2,3,4
        }
       
        2.For loop for print numbers from 1 to 10 with continue
       
        for(int i=1;i<=10;i++)             //Initialization,Conditional,incremental/decrement
        {
            if(i==5)
            {
                continue;
            }
            System.out.println(i);          //1,2,3,4,6,7,8,9,10 :5 is not printed
        }


Increment And Decrement Operator In JAVA

      Increment operator: ++
      Decrement operator: --
     
1. Post increment
        int a=1;
        int b=a++;                             //post increment
        System.out.println(a); //2
        System.out.println(b); //1

 2.Pre increment  
        int c=1;
        int d=++c;                               //pre increment
        System.out.println(c); //2
        System.out.println(d); //2
      
3.Post decrement
        int e=2;
        int f=e--;                                 //post decrement
        System.out.println(e); //1
        System.out.println(f); //2
  
4.Pre decrement   
        int g=2;
        int h=--g;                                //pre decrement
        System.out.println(g); //1
        System.out.println(h); //1